Multimedia Broadcast and Multicast Services (MBMS) is a point-to-multipoint service in which data is transmitted from an access node to multiple wireless devices. Applications of an MBMS system include audio, video, and multimedia broadcasts, emergency alerts, traffic announcements, map information to wireless devices in a similar geographic area, and the like.
A mechanism such as hybrid automatic repeat request (HARQ) protocol can be used in an MBMS system to improve transmission reliability over a wireless communication link. The HARQ protocol can enable retransmission requests to be sent by a receiving wireless device in the event that expected data is lost or is not decodable (for example, if the data is corrupted). However, HARQ retransmission requests increase data latency in the larger communication network because data is typically retransmitted until it is correctly decoded at a receiving wireless device.
Further, where data is lost or corrupted in an MBMS system, each receiving device which fails to receive the data may send a retransmission request, numerous wireless devices may transmit retransmission requests for the lost or corrupted data, potentially leading to congestion in both the uplink and downlink portions of a wireless communication link. Consequently, in many MBMS systems, mechanisms such as HARQ are disabled. While this reduces network congestion and signaling overhead, the broadcast data is more susceptible to errors introduced by wireless communication.